SUNRPC: Refactor rpc_clone_client()

rpc_clone_client() does most of the same tasks as rpc_new_client(),
so there is an opportunity for code re-use.  Create a generic helper
that makes it easy to clone an RPC client while replacing any of the
clnt's parameters.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 43 insertions, 40 deletions

diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index fa48c60aef23..afbeefab6600 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -490,59 +490,62 @@ EXPORT_SYMBOL_GPL(rpc_create);
  * same transport while varying parameters such as the authentication
  * flavour.
  */
-struct rpc_clnt *
-rpc_clone_client(struct rpc_clnt *clnt)
+static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
+                                           struct rpc_clnt *clnt)
 {
-        struct rpc_clnt *new;
         struct rpc_xprt *xprt;
-        int err = -ENOMEM;
+        struct rpc_clnt *new;
+        int err;
 
-        new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
-        if (!new)
-                goto out_no_clnt;
-        new->cl_parent = clnt;
-        /* Turn off autobind on clones */
-        new->cl_autobind = 0;
-        INIT_LIST_HEAD(&new->cl_tasks);
-        spin_lock_init(&new->cl_lock);
-        rpc_init_rtt(&new->cl_rtt_default, clnt->cl_timeout->to_initval);
-        new->cl_metrics = rpc_alloc_iostats(clnt);
-        if (new->cl_metrics == NULL)
-                goto out_no_stats;
-        if (clnt->cl_principal) {
-                new->cl_principal = kstrdup(clnt->cl_principal, GFP_KERNEL);
-                if (new->cl_principal == NULL)
-                        goto out_no_principal;
-        }
+        err = -ENOMEM;
         rcu_read_lock();
         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
         rcu_read_unlock();
         if (xprt == NULL)
-                goto out_no_transport;
-        rcu_assign_pointer(new->cl_xprt, xprt);
-        atomic_set(&new->cl_count, 1);
-        err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
-        if (err != 0)
-                goto out_no_path;
-        rpc_clnt_set_nodename(new, utsname()->nodename);
-        if (new->cl_auth)
-                atomic_inc(&new->cl_auth->au_count);
+                goto out_err;
+        args->servername = xprt->servername;
+
+        new = rpc_new_client(args, xprt);
+        if (IS_ERR(new)) {
+                err = PTR_ERR(new);
+                goto out_put;
+        }
+
         atomic_inc(&clnt->cl_count);
-        rpc_register_client(new);
-        rpciod_up();
+        new->cl_parent = clnt;
+
+        /* Turn off autobind on clones */
+        new->cl_autobind = 0;
+        new->cl_softrtry = clnt->cl_softrtry;
+        new->cl_discrtry = clnt->cl_discrtry;
+        new->cl_chatty = clnt->cl_chatty;
         return new;
-out_no_path:
+
+out_put:
         xprt_put(xprt);
-out_no_transport:
-        kfree(new->cl_principal);
-out_no_principal:
-        rpc_free_iostats(new->cl_metrics);
-out_no_stats:
-        kfree(new);
-out_no_clnt:
+out_err:
         dprintk("RPC:       %s: returned error %d\n", __func__, err);
         return ERR_PTR(err);
 }
+
+/**
+ * rpc_clone_client - Clone an RPC client structure
+ *
+ * @clnt: RPC client whose parameters are copied
+ *
+ * Returns a fresh RPC client or an ERR_PTR.
+ */
+struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
+{
+        struct rpc_create_args args = {
+                .program        = clnt->cl_program,
+                .prognumber     = clnt->cl_prog,
+                .version        = clnt->cl_vers,
+                .authflavor     = clnt->cl_auth->au_flavor,
+                .client_name    = clnt->cl_principal,
+        };
+        return __rpc_clone_client(&args, clnt);
+}
 EXPORT_SYMBOL_GPL(rpc_clone_client);
 
 /*